Monthly Archives: March 2013

How important is sleep? The evidence piles up every week, with UC Davis Sleep Laboratory researchers adding their wisdom in the February issue of American Journal of Physiology: Regulatory, Integrative and Comparative Physiology.

The new study “Longitudinal Sleep EEG trajectories indicate complex patterns of adolescent brain maturation” monitored brain waves of sleeping adolescents, documenting major changes in the brain as it “prunes away neuronal connections” and transitions from childhood to adulthood.

“We’ve provided the first long-term, longitudinal description of developmental changes that take place in the brains of youngsters as they sleep,” said Irwin Feinberg, professor emeritus of psychiatry and behavioral sciences and director of the UC Davis Sleep Laboratory. “Our outcome confirms that the brain goes through a remarkable amount of reorganization during puberty that is necessary for complex thinking.”

The research also confirms that electroencephalogram, or EEG, is a powerful tool for tracking brain changes during different phases of life, and that it could potentially be used to help diagnose age-related mental illnesses. According to Science Daily, the research is the final component in a three-part series of studies carried out over 10 years and involving more than 3,500 all-night EEG recordings.

The new findings show that synaptic density in the cerebral cortex reaches its peak at age 8 and then begins a slow decline. The recent findings also confirm that the period of greatest and most accelerated decline occurs between the ages of 12 and 16-1/2 years, at which point the drop markedly slows.

“Discovering that such extensive neuronal remodeling occurs within this 4-1/2 year timeframe during late adolescence and the early teen years confirms our view that the sleep EEG indexes a crucial aspect of the timing of brain development,” said Feinberg.

Sleep disturbances are common in people with Alzheimer’s disease, but it wasn’t previously known prior to this study if they occur before cognitive symptoms begin. Washington University School of Medicine researchers were seeking to learn if poor-quality sleep is an early indicator of Alzheimer’s.

For the new study, they recruited 142 adults age 45 and older with no outward signs of cognitive problems. Researchers monitored their sleep for two weeks and also tested their cerebral spinal fluid to see if a molecule that indicates a buildup of beta-amyloid – regarded as the earliest identifiable stage of Alzheimer’s– was occurring in their brains.

They found that 32 people who had evidence of the molecule in their cerebral spinal fluid also had the poorest quality sleep of those in the study.

In the study’s conclusions, the researchers said they hoped their findings would stimulate more research into the area of sleep and amyloid disposition, and provide an even stronger motivation to identify and treat individuals with common sleep disorders, such as obstructive sleep apnea. Apnea causes people to briefly stop breathing and to sleep fitfully.

The study did not show that it is a certainty that people with beta-amyloid deposits will go on to develop Alzheimer’s disease.

The take-home message of this study is that if someone is having sleep problems they should go to the doctor because it could be an early indicator of Alzheimer’s disease, or it can indicate another problem like sleep apnea, which is correctable.

Researchers at the University of Montreal examined a wide swath of literature, concluding that much of sleepwalkers’ behavior comes down to myth. For example, sleepwalkers sometimes remember what they have done on their night time sojourns.

Antonio Zadra, of the University of Montreal, worked with colleagues at the Centre for Advanced Studies in Sleep Medicine at the Hôpital du Sacré-Cœur de Montréal, with findings published in Lancet Neurology “”Somnambulism: clinical aspects and pathophysiological hypotheses” Read Summary

“In adults, a high proportion of sleepwalkers occasionally remember what they did during their sleepwalking episodes,” said Zadra via University of Montreal press release “Some even remember what they were thinking and the emotions they felt.”

Zadra concludes that the behavior of sleepwalkers is not simply a zombie-like automatic function. “There is a misconception that sleepwalkers do things without knowing why,” he said. “However, there is a significant proportion of sleepwalkers who remember what they have done and can explain the reasons for their actions.”

Both children and adults are in a state of so-called dissociated arousal during wandering episodes—with parts of the brain asleep, while other parts are awake. “There are elements of wakefulness since sleepwalkers can perform actions such as washing, opening and closing doors, or going down stairs,” added Zadra. “Their eyes are open and they can recognize people. But there are also elements specific to sleep: sleepwalkers’ judgment and their ability for self-thought are altered, and their behavioral reactions are nonsensical.”

Published in the JAMA Network “Primary Care vs Specialist Sleep Center Management of Obstructive Sleep Apnea and Daytime Sleepiness and Quality “, a 155-patient study concluded “primary care was not clinically inferior to treatment at a specialist sleep center for improvement in daytime sleepiness scores.” According to an abstract, the primary outcome comparison was a 6-month change in Epworth Sleepiness Scale (ESS) score.

Both primary care and specialty groups brought ESS scores down to seven from roughly 12 in 6 months. The abstract concludes: “Among patients with obstructive sleep apnea, treatment under a primary care model compared with a specialist model did not result in worse sleepiness scores, suggesting that the two treatment modes may be comparable.”

Ching Li Chai-Coetzer, MBBS, PhD, of the Adelaide Institute for Sleep Health, Repatriation General Hospital, Daw Park, South Australia, and colleagues write that “a simplified management strategy for obstructive sleep apnea based in primary care was not clinically inferior to standard care in a specialist sleep center.”

“Thus, with adequate training of primary care physicians and practice nurses, and with appropriate funding models to support an ambulatory strategy,” they continue via JAMA press release, “primary care management of obstructive sleep apnea has the potential to improve patient access to sleep services. This would be particularly beneficial for rural and remote regions, as well as developing nations, where access to specialist services can be limited.”

Patients with heart failure routinely suffer from insomnia, but does insomnia increase the risk of heart failure?

Researchers in Norway spent more than a decade studying the question, concluding that insomnia caused more than a three-fold increase in heart failure risk.

The study, “Insomnia and the risk of incident heart failure: a population study“ published online last week in the European Heart Journal, followed 54,279 people between the ages of 20-89 for an average of more than 11 years.

According to a summary prepared by the European Society of Cardiology, Dr Lars Laugsand, a post-doctoral fellow in the Department of Public Health, Norwegian University of Science and Technology, Trondheim, related heart failure risk “to three major insomnia symptoms, including trouble falling asleep, problems staying asleep, and not waking up feeling refreshed in the morning.”

Laugsand’s study found that persons suffering from insomnia “have increased risk of having heart failure. Those reporting suffering from all three insomnia symptoms simultaneously were at considerably higher risk than those who had no symptoms or only one or two symptoms.”

An abstract in the European Heart Journal details researchers’ conclusions that insomnia is specifically associated with an increased risk of incident heart failure. “If our results are confirmed by others and causation is proved,” write researchers, “evaluation of insomnia symptoms might have consequences for cardiovascular prevention.”

The authors also found a moderate risk increase related to individual insomnia symptoms. However, risk among those with “all three insomnia symptoms simultaneously” was particularly high even after adjustment for established cardiovascular risk factors and psychological distress.

Academia and mass media continued their convergence with the widespread reporting of new Surrey University research that concludes “getting too little sleep for several nights in a row disrupts hundreds of genes that are essential for good health.”

According to a recent report, tests on people who slept less than six hours a night for a week revealed substantial changes in the activity of genes that govern the immune system, metabolism, sleep and wake cycles—in addition to the body’s response to stress—suggesting that poor sleep “could have a broad impact on long-term wellbeing.”

Effects of insufficient sleep on circadian rhythmicity and expression amplitude of the human blood transcriptome
publishing in the Proceedings of the National Academy of Sciences recent Feb edition.

The text of the study’s abstract specifically states “insufficient sleep and circadian rhythm disruption are associated with negative health outcomes, including obesity, cardiovascular disease, and cognitive impairment.”

The changes, which affected more than 700 genes, may shed light on the biological mechanisms that raise the risk of a host of ailments, including heart disease, diabetes, obesity, stress and depression, in people who get too little sleep.

“The surprise for us was that a relatively modest difference in sleep duration leads to these kinds of changes,” said Professor Derk-Jan Dijk, director of the Surrey Sleep Research Centre at Surrey University, in the Guardian report. “It’s an indication that sleep disruption or sleep restriction is doing more than just making you tired.”

Previous studies have suggested that people who sleep less than five hours a night have a 15% greater risk of death from all causes than people of the same age who get a good night’s sleep.

Even low-end estimates of fatalities related to drowsy driving confirm that the problem exacts a tragic toll on the nation’s highways. According to the National Highway Traffic Safety Administration (NHTSA), 2.5% of fatal motor vehicle crashes (approximately 730 in 2009), and 2% of all crashes with nonfatal injuries (approximately 30,000 in 2009), involve drowsy driving.

Still other modeling studies suggest 15% to 33% of fatal crashes might involve drowsy drivers. Either way, the figures lend additional credence to efforts to get the trucking industry fully on board with additional testing and treatment for commercial drivers.

The latest data from the NHTSA and the Centers for Disease Control (CDC) show that fatalities and injuries are more likely in motor vehicle crashes that involve drowsy driving compared with non-drowsy driving crashes.

To assess the state-level self-reported prevalence of falling asleep while driving, CDC analyzed data from a set of questions about insufficient sleep administered through the Behavioral Risk Factor Surveillance System (BRFSS) during 2009–2010.

Among 147,076 respondents in 19 states and the District of Columbia (DC), 4.2% reported having fallen asleep while driving at least one time during the previous 30 days. Reports of falling asleep while driving were more common among adults who reported usually sleeping ≤6 hours per day, snoring, or unintentionally falling asleep during the day compared with other adults who did not report these characteristics.

Drowsy driving was associated with other sleep-related characteristics. Adults who reported frequent insufficient sleep, a daily sleep duration of ≤6 hours, snoring, or unintentionally falling asleep during the day reported drowsy driving more frequently than those who did not report those characteristics. Click here for the full CDC report.